Invertebrates

Invertebrates are animals without a backbone. Some, like oysters and blue crabs, are easy to recognize. But others like worms and copepods, some of the most abundant animals in the Bay, are rarely seen by humans.

Also known as the sand crab, the Atlantic ghost crab is a sand-colored crustacean with a distinct pair of white claws. Ghost crabs are active on coastal beaches in the Chesapeake Bay region from spring through autumn.

The Chinese mitten crab is a light brown crustacean with a distinct pair of hairy, white-tipped claws. Native to East Asia, the invasive species has been reported in small numbers in the Chesapeake Bay.

Also known as the portly spider crab or the nine-spined spider crab, the common spider crab is a long-legged and slow-moving crustacean that covers itself in algae and small debris as a defense against predators.

The devil crayfish is a brownish red crustacean that resembles a miniature lobster. They typically have red-tipped claws. They can be found burrowing in forested areas where the water table is near the surface.

The ghost anemone is a jelly-like invertebrate with a flat, rounded base and stinging tentacles at the top of an elongated stalk. It lives on rocks, reefs, pilings and other hard surfaces throughout the Chesapeake Bay.

The hooked mussel is a bivalve whose dark, ridged shell is strongly curved, or “hooked” on one end. It is prolific in oyster reefs—often “wrapping up” oysters—and can outnumber the amount of oysters by several fold.

The rusty crayfish is an invasive species that can be found in some rivers and streams in Maryland, New York, Pennsylvania, Virginia and West Virginia. It has a spot on either side of its back that is rusty in color.

The zebra mussel is a tiny bivalve with zebra-like stripes on its triangular shell. It lives in freshwater lakes, rivers, streams and reservoirs in parts of the Chesapeake Bay watershed. It is a non-native and invasive species.